Electrical boxes are typically used to hold electrical outlets, switches, and the terminal portions of related wires in the walls of residential and commercial buildings. Electrical boxes are also used to provide mounting locations and wiring connections for fans and other electrical appliances. Electrical boxes are manufactured in a variety of sizes. They are in practice commonly fastened to structural members, such as metal or wooden studs, forming the walls of the building.
A duplex-sized electrical box 10 is shown in FIG. 1 mounted to a stud 16. As is typical, the electrical box 10 has a rear wall and four side walls that cooperate to define an open inner volume. The electrical box 10 has a front opening 12. Once electrical wires 14 are installed, terminal portions of the wires 14 are disposed within the open inner volume of the box 10, potentially protruding through the front opening 12 of the electrical box 10. For wall mounting, electrical boxes 10 may, by way of non-limiting examples, be duplex sized, quad sized, 3-gang, or occasionally even larger.
Normally, wallboard is mounted over the structural members to close the wall and to act as a surface material. It is necessary to cut openings in the wallboard sheets in accurate alignment with the electrical boxes 10. However, in doing so, care must be taken to avoid damage to the electrical box 10 or the wiring 14 within and leading to the electrical box 10.
One strategy for producing an accurately located hole in the wallboard is to measure the location of the electrical box 10 relative to the planned placement of the wallboard sheet and then to pre-cut an opening in the wallboard sheet. However, such measuring is cumbersome. If the measurements are in error, the cut hole is misaligned, and the wallboard sheet is ruined. To avoid this, it is often seen as more efficient to attach the sheet of wallboard over the electrical box 10 and then use a cutting device, such as a utility knife or a rotary power tool, to cut away the wallboard over the electrical box 10. Unfortunately, this method still leaves risk of misalignment or other incorrect cutting, which would require repair or replacement of the wallboard. Even worse, there is a substantial risk of accidentally cutting or damage to the electrical wires 14, which entails still greater repair expense and inconvenience.
A number of tools and templates have been disclosed by the prior art with the goal of making the cutting of electrical box openings in wallboard more accurate and efficient. One such prior art device for locating electrical boxes to facilitate the accurate cutting of openings during wallboard installation is taught in U.S. Pat. No. 7,432,444, entitled Temporary Protective Cover for an Electrical Box. There, a temporary protective cover is applied over an electrical box, and a protruding pin extends from the protective cover. When the wallboard is mounted over the electrical box, the protruding pin indicates the location of the box by forming a bump in the wallboard. Based on the indicated location of the box, an opening can be cut in the wallboard approximately corresponding with the shape and location of the electrical box. There are further, substantially similar, guides and templates disclosed by the prior art.
However, even with such guides, cutting openings in the wallboard presents several challenges and risks. For instance, if a utility knife is used, there is considerable variation in the accuracy of the opening depending on the skill of the user and the sharpness of the blade. In this regard, it is recognized that wallboard material typically dulls cutting blades very quickly. Moreover, even with a dull blade, slipping with a utility knife can cause serious hand injuries, damage to electrical wiring, or both. Where a rotary cutter is used, the quality of the result again depends largely on the skill of the user, and rotary cutters have their own potential for user injuries and wire damage. In any case, the cutting of openings in wallboard using prior art guides and templates remains a time consuming and laborious task.
Other known prior art cutting devices employ guide pins that are received into the screw apertures of a typical plastic receptacle box to guide in the application of a cutting plate that has four cutting blades disposed in a rectangular configuration. The cutting plate is hammered into the wallboard in an attempt to cause the cutting blades to cut a square opening in the wallboard corresponding to the shape and location of the electrical box. However, such cutting devices have limitations and shortcomings. Most basically, use of the device relies on hammering the cutting plates and blades with sufficient force to cut through the wallboard. This applies substantial localized pressure, which can dent and otherwise damage the wallboard. Moreover, effective cutting relies on the cutting blades being sharp, and sharpening the blades is of limited practicability. With that, the performance of the tool will invariably degrade, and the likelihood of damage to the wallboard is increased. Even further, such cutters have limited utility to electrical boxes that do not have front nailing bars or other hardware extending beyond the perimeter of the box that would be likely to be impacted by the cutting blades to damage them and impair their operation.
In light of the foregoing, it is apparent that there is a need in the art of wallboard installation for a device that permits the cutting of openings in wallboard for electrical boxes of substantially any type and configuration accurately and efficiently with minimized risk of injury to the user.